NISCAIR Online Periodicals Repository Collection: IJC-A Vol.47A(05) [May 2008]http://nopr.niscair.res.in/handle/123456789/2069
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Statistical analysis on quencher in photobiological applicationhttp://nopr.niscair.res.in/handle/123456789/2102
Title: Statistical analysis on quencher in photobiological application
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<br/>Authors: Datta, Jaydip; Bhattacharjee, Chiranjib; De, B R
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<br/>Abstract: The Stern-Volmer equation has been analysed statistically through linear regression or best fit method in presence of a quencher. Two important statistical parameters like regression coefficient and correlation coefficient are calculated from the standard data. The data obtained by the tryptophan fluorescence by dissolved oxygen gas as quencher at 348 nm has been analysed. The values of two most important photochemical kinetic parameters, the rate constant in presence of quencher and observed fluorescence lifetime in absence of quencher are calculated. The values obtained by this type of analysis are: 1.27610¹⁰ L.mol⁻¹.s⁻¹ and 2.610⁻¹⁰ s respectively, with a correlation coefficient value of 1.000. This statistical data analysis is used to interpret the mechanism of bimolecular quenching which can be applied to photobiological study in the accessibility of amino acid residues of a folded protein to solvent.
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<br/>Page(s): 708-710Mon, 28 Apr 2008 22:58:59 GMTOscillating behaviour of gallic acid – methyl ketone system catalysed by metal ionshttp://nopr.niscair.res.in/handle/123456789/2100
Title: Oscillating behaviour of gallic acid – methyl ketone system catalysed by metal ions
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<br/>Authors: Lone, Mushtaq A; Nath, Masood A; Ganaie, Nadeem B; Peerzada, Mustafa G
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<br/>Abstract: Studies on oscillatory behaviour of gallic acid with potassium bromate in presence of methyl ketones as co-substrates and various metal-ions as catalysts in aqueous acid medium are reported here. The investigations establish the order of reactivity of single and mixed organic substrate systems and also explore the relative efficiency of metal ions as catalysts in the reaction systems. The Mn²⁺/Fe²⁺ couple has been examined for co-catalyst effect on both single and mixed organic substrate systems.
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<br/>Page(s): 705-707Mon, 28 Apr 2008 22:58:59 GMTBorohydride reduction of azomethine bonds in β-alanine Schiff base complexeshttp://nopr.niscair.res.in/handle/123456789/2099
Title: Borohydride reduction of azomethine bonds in β-alanine Schiff base complexes
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<br/>Authors: Yalçın, Bahattin; Medjidov, Ajdar Akbar; Nasrullayeva, Tarana Malik; Taşcıoğlu, Sülin; Aydın, Adnan
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<br/>Abstract: Borohydride reduction of the azomethine bond in the Schiff base complexes of β-alanine has been studied. Ni(II), Pd(II) and Pt(II) complexes of N-β-carboxyethyl-2-hydroxynaphthylideneimine (L¹H₂), N-β-carboxyethyl-2-hydroxybenzylideneimine (L²H₂), and N-β-carboxyethyl-N-2-hydroxynaphtylmethyleneamine (L3H₂) have been prepared. L¹H₂ forms complexes with palladium as Pd(L¹H)₂, in which carboxylic groups do not participate in the coordination. L²H₂ and L3H2 behave as tridentate double charged ligands, giving complexes of the type ML².nH₂O and ML³.nH₂O. Ni(II) gives binuclear complex [NiL³.2H₂O]₂. No visible reaction of –C=N- bond reduction with borohydride has been observed for the L¹H₂ complexes of Co(III) d⁶, Ni(II) d⁸, Pd(II) d⁸, Zn(II) d¹⁰ ions at 25ºС in dimethyl formamide. This tendency has also been observed for Ni(II) complex of salicylaldehyde based β-alanine Schiff base, L²H₂, as well as Ni(II), Pd(II), Zn(II) complexes of salen. However, the C=N bond can be reduced with borohydride when it coordinates the metal ions, Cu(II), Co(II) and Mn(II). Ni(II) complexes of both Schiff bases are inactive against reduction. The reduction rates of Schiff bases and related activation energies have also been determined.
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<br/>Page(s): 699-704Mon, 28 Apr 2008 22:58:59 GMTTheoretical study on magnetic coupling interactions of the binuclear copper(II) complexeshttp://nopr.niscair.res.in/handle/123456789/2098
Title: Theoretical study on magnetic coupling interactions of the binuclear copper(II) complexes
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<br/>Authors: Miao, Ti-fang; Li, Shuang
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<br/>Abstract: The density functional theory (DFT) has been used to calculate magnetic coupling constants of binuclear copper(II) complexes. The results show that the coupled interaction between two magnetic centers is antiferromagnetic. The influence of electronegativity of atom far away from two magnetic centers on magnetic coupling interactions has been analyzed. The obtained results may be useful as reference for synthesis of the new functional complex and the molecular assembly analysis.
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<br/>Page(s): 695-698Mon, 28 Apr 2008 22:58:59 GMT